[sdiy] Simple VCA?

[Paul Perry]

I don't know exactly what is going on either, Ingo, but think about this - 
Putting an infinite resistor across the inputs would do nothing.
But imagine if you put a zero ohm resistor across there - that would
certainly shut off the gain.
So the two extreme cases do something!
The question now is to make it linear ;D

paul perry Melbourne Australia 
-----Original Message-----
I just don't understand how this would work. When the feedback loop  
is working correctly there's virtually zero voltage between the two  
inputs of the opamp. There would be no current through a resistor,  
variable or not, between the two inputs, so this resistor doesn't do  
anything.
What am I missing?